The invention herein relates to a hose in accordance with the preamble of claim 1.
Hoses of the type addressed herein have been known. They are used to transport gaseous and fluid media in applications in the automobile industry, for example, where they are installed in air-conditioning systems and/or steering aid systems. They are produced xe2x80x9cby the meterxe2x80x9d by the manufacturer and cut to a desired length. The end regions of hoses manufactured in this manner must be prepared in such a manner that the hoses can be suitably integrated in a system for the transport of preferably gaseous media. To achieve this, at least one end is provided with an insertion element, also called a fitting, which is inserted in this end. The hoses addressed herein have a corrugated interior surface. Therefore, they have elevations and depressions in that region. It is necessary that the hose create a tight seal with the insertion element, so that media may be transported even at high pressure, without having the media to be transported leak out in the region of the insertion element. The insertion element which is inserted in at least one end of the hose projects beyond the end of the hose and may be tightly connected with a connecting site so that a seal is created. In so doing, it is possible to connect the hose with an appropriate element inside the arrangement which serves for the transport of the gaseous medium, as well as connect hose ends with each other.
It has been found that in different operating states it is not possible to create a lasting, tight seal between the insertion element and the associate hose end. In some cases the connection between hose and insertion element has even come apart.
Therefore, the problem to be solved by the invention herein is to provide a hose which permits a tight connection, creating a seal between the hose and the insertion element.
This problem has been solved by means of a hose, which exhibits the features disclosed by claim 1. The hose is characterized by at least one gasket element provided in the area of contact between the interior surface of the hose and the exterior surface of the insertion element, said gasket consisting of a crystalline, in particular metallic, material, preferably of a lead or copper alloy. In so doing, the gasket element prevents the medium transported through the hose from leaking out so that it cannot damage the area of contact between the interior surface of the hose and the exterior surface of the insertion element. Consequently, this ensures on one hand that the connection between hose and insertion element remains continuously tight and on the other hand that this connection will not come apart.
In the case of a preferred example of embodiment of the hose the material of the gasket element is softer than the material of the interior surface of the hose. Consequently, the gasket element, which, prior to insertion of the insertion element, is located in the depressions of the interior surface of the hose, is deformed in a plastic or elastic manner when the insertion element is inserted, thereby creating a force-closed connection due to adhesive friction between the gasket element and the interior surface of the hose and/or a form-closed connection due a notch or groove on the gasket element between the gasket element and the interior surface of the hose.
One of the features of a preferred form of embodiment of the hose is that the depression is created by a peripheral groove created on an imaginary helical line. This embodiment facilitates insertion of the gasket elementsxe2x80x94which, in that case, are configured as open ringsxe2x80x94into the inside of the hose. Therefore, the gasket elements used here follow the helical depression. Their length can be adapted to the individual situation that requires a seal. Furthermore, it is possible to use gasket elements which extend more than once around the exterior surface of the insertion element. In this instance, analogous to the ring-shaped gasket elements, it is possible to insert gasket elements in adjacent grooves or depressions.
In another preferred example of embodiment of the hose the gasket element has a circular or polygonal, preferably triangular or trapezoidal, cross-section. The circular cross-section of the gasket element provides a particularly large surface, which may come into force-closed engagement with the interior surface of the hose. The polygonal cross-section permits the abutment of the gasket element in an edge region of the interior surface of the hose or the exterior surface of the insertion element, so that particularly high compressive forces per unit area are developed, said forces permitting a safe seal even at high pressure.
Another preferred example of embodiment of the hose features an insertion element of stainless steel, plastic material, polyamide or the like. The choice of these materials has the advantage that they can be handled without problems and that, therefore, the insertion elements are easy to manufacture.
Additional preferred examples of embodiment are disclosed by the remaining Subclaims.